Although China Southern has left Skyteam, it is still partners with Delta and Airfrance. Both websites can be used to find CZ award space (albeit glitchy). Sometimes, Delta.com will show e.g. XYZ-CAN having award space (where XYZ is some random mainland Chinese city). Likewise, Delta.com will show CAN-LAX as having 1 economy award seat (trying for 2 errors out). If you search Delta.com for XYZ-LAX via CAN, it becomes unbookable.

Likewise with AA, I tried for one date via the phone, and KHN-CAN-LAX was unbookable as an award, but CAN-LAX was bookable for 37,500 AAdvantage miles + $31.17.
It looks like there might be some married inventory logic going on.

For CAN-LAX only:
Delta charges 62,500 skymiles for economy award + 1102 Yuan, which is the total of:

• 26 Yuan US APHIS Passenger Fee Passengers (XA)
• 140 Yuan China airport fee (CN)
• 39 Yuan US Customs User Fee (YC)
• 45 Yuan US Immigration User Fee (XY)
• 26 Yuan carrier-imposed surcharge (YQ)
• 700 Yuan carrier-imposed surcharge (YR)
• 126 Yuan US International Arrival Tax (US)

For the same route, AA charges 37,500 AAdvantage miles, plus XA, CN, YC, XY (250 Yuan).

For the same route, AirFrance charges 46,000 Flying Blue miles, plus XA, CN, YC, XY, YQ, YR, US (same taxes/fees as Delta).